1. Field of the Invention
The present invention relates to an organic light-emitting display apparatus and a method of manufacturing the same, and more particularly, to an organic light-emitting display apparatus and a method of manufacturing the same by which the number of mask uses can be reduced during manufacturing of the organic light-emitting display apparatus and a defect in coating an organic layer in a pad region can be corrected.
2. Description of the Related Art
An organic light-emitting display apparatus is manufactured on a substrate on which a pattern including a thin-film transistor (TFT), a capacitor, and wiring connecting the TFT and the capacitor is formed.
Generally, a fine structure pattern including a TFT and so forth is transferred to an array substrate by using a mask on which the fine structure pattern is printed so that the substrate on which the organic light-emitting display apparatus is manufactured can be patterned.
Pattern transfer using a mask is generally performed using a photolithography method. According to the photolithography method, photoresist is evenly applied on a substrate on which a pattern is to be formed. The photoresist is exposed to light by using photolithography equipment, such as a stepper, and the light-sensitive photoresist is developed (in the case of positive photoresist). Furthermore, after the photoresist is developed, the remaining photoresist is used as a mask for etching a pattern, and the remaining photoresist is then removed.
In the process of transferring a pattern by using the mask, as described above, it is necessary to prepare the mask having a required pattern, and thus the cost of fabricating the mask increases as more operations are performed using the mask. Therefore, to solve this problem, a structure capable of reducing the number of mask uses is needed.
As an approach to reduce the number of mask uses, a scheme for forming an organic layer, which functions as a pixel defining layer, with a large thickness of 3 μm or more to avoid a need to form a separate spacer has been considered. In this scheme, however, stress on the thick organic layer increases so that coating is not performed appropriately, especially in a pad region which is an end portion of the organic layer, resulting in a lifting phenomenon. Therefore, there is a need for a scheme capable of reducing the number of mask uses and avoiding a problem caused by an organic layer coating defect.